1. Field
Exemplary embodiments of the present invention relate to a fuse circuit used for storing diverse data in a variety of semiconductor devices.
2. Description of the Related Art
Generally, a data of a fuse is recognized based on whether the fuse is cut or not. The fuse may be cut by using a laser. While programming a fuse of a semiconductor device in the wafer stage thereof, however, it is difficult to program the fuse by using a laser after the wafer is mounted in a package.
Therefore, an anti-fuse, which is also known as an e-fuse, is used. The anti-fuse, or e-fuse, stores data by using a transistor and changing the resistance between a gate and a drain/source of the transistor.
FIG. 1 is a schematic diagram illustrating an anti-fuse which is formed of a transistor and operates as a resistor or a capacitor.
Referring to FIG. 1, the anti-fuse is formed of a transistor T, and a power supply voltage is applied to a gate G of the transistor T while a ground voltage is applied to the drain/source D/S thereof.
When a power source voltage a level of which the transistor T may endure is applied to the gate G, the anti-fuse operates as a capacitor C. Therefore, no current flows between the gate G and the drain/source D/S. However, when a high level of power source voltage that the transistor T may not endure is applied to the gate G, the gate oxide of the transistor T is destroyed to short-circuit the gate G and the drain/source D/S from each other and as a result the anti-fuse operates as a resistor R. Therefore, current flows between the gate G and the drain/source D/S.
According to this phenomenon, the anti-fuse recognizes a data based on the resistance value between the gate G and the drain/source D/S of the anti-fuse. To recognize the data of the anti-fuse, 1) the anti-fuse directly recognizes the data without performing an amplification operation by enlarging the size of the transistor T, or 2) the anti-fuse recognizes the data by including an amplifier instead of enlarging the size of the transistor T and sensing/amplifying the current flowing through the transistor T. Since the two methods require a large transistor T or an amplifier for amplifying data, there is limitation in terms of area.